The Center for Positive/Empirical Analysis of Political Economy, Waseda University Top Global University (TGU) Project, will invite Dr. Naoki Egami (Assistant Professor of Columbia University) to deliver a special lecture titled “Empirical Strategies toward External Validity” on Dec. 7. Dr. Egami is a very active young researcher in US political science, specialising in political science methodology. Previously, he gave a talk at Waseda University while he was a post-doctoral fellow at Princeton University. We look forward to your participation.
Event Information
Speaker: Prof. Naoki Egami (Assistant Professor, Department of Political Science, Columbia University)
Title: Empirical Strategies Toward External Validity
Date and Time: December 7 (Thu), 13:10-14:50
Venue: Waseda Campus Bldg. 3, Room 606
Registration: Not Required
Language: English
Open to members of Waseda University and the general public
Organizers: Tago Atsushi ([email protected]) / Yuriko Takahashi ([email protected])
Sponsored by the Center for Empirical Analysis of Political Economy, Top Global University Project
Abstract
Over the last few decades, social scientists have developed and applied a host of statistical methods to make valid causal inferences, known as the credibility revolution. This trend has primarily focused on internal validity—researchers aim to unbiasedly estimate causal effects within a study. However, one of the most important long-standing methodological debates is about external validity—how scientists can generalize causal findings beyond a specific study. This question of external validity has a long history in the social sciences, going back to at least the 1960s, and it has recently become even more essential, given that huge opportunities and challenges of accumulating causal knowledge have become evident.
In this talk, I will discuss a unified pipeline for external validity, consisting of a framework, study design, and data analysis. First, I will introduce a framework of external validity (Egami and Hartman, 2022; APSR) that synthesizes diverse external validity concerns. Then, I will discuss how to design studies for external validity (Egami and Lee, 2023). In particular, I examine a question of the site/case selection, e.g., where should we run experiments, and which cases should we examine? I propose a general method to systematically select diverse study sites for external validity. This new approach, which I call synthetic purposive sampling, combines ideas from the synthetic control method in the causal inference literature and purposive sampling in the research design literature. It offers a new statistical foundation to design causal studies for external validity. I introduce our companion R package spsR (https://naokiegami.com/spsR). Finally, if time permits, I will also discuss how to assess the robustness of causal findings to external validity bias (Devaux and Egami, 2022). This measure of external robustness is particularly useful when researchers analyze randomized experiments that were designed without explicit external validity consideration.
